BS EN ISO 11173:2017 pdf download

BS EN ISO 11173:2017 pdf download.Thermoplastics pipes – Determination of resistance to external blows – Staircase method
1 Scope
This international Standard specifies a method for determining the resistance to external blows of ther- maplastic pipes of circular cross-section; it is called the staircase method. This method is applicable to isolated batches of pipe to be testedat 0 °C. NOTE 1 If testing below 0。C is necessary, the tempera- ture of – 20 °C is recommended.
2 Normative reference
The following standard contains provisions which, through reference in this text, constitute provisions of this International Standard. At the time of publication, the edition indicated was valid. All standards are subject to revision, and parties to agreements based on this Internationa! Standard are encouraged to investigate the possibility of applying the most recent edition of the standard indicated below. Members of IEC and ISO maintain registers of currently valid International Standards.
ISO 6603-1:1985, Plastics – Determination of multi- axial impact behaviour of rigid plastics 一Part 1: Falling dart method.
3 Definitions
For the purposes of this Internationa! Standard, the following definitions apply. 3.1 drop height for 50 % failure, Hso: Height of fall of a striker of specified mass, which provokes failure of 50 % of test pieces from samples of pipe taken to represent a batch.
4 Principle
Test pieces, comprising cut lengths of pipe, are each subjected to a single blow by a falling striker of specified mass and shape dropped from one of a sequence of different heights onto a random position around the circumference of the pipe. If a test piece fails, the drop height for the next blow is decreased by a predetermined amount. If a test piece does not fail, the drop height for the next blow is increased accordingly. If sufficient test pieces are used, the Hso value of a batch, or a production run from an extruder, can be calculated. The severity of this test method can be adjusted by changing the mass of the striker and/or the test temperature.
5 Apparatus
5.1 Failing-weight testing machine, incorporating the following basic components (see figure 1).
5.1.1 Main frame, with guide rails or a guiding tube rigidly fixed in the vertical position, to accommodate a striker (5.1.2) and release it to fall vertically and freely. When calibrated, the speed of the striker at the moment of impact shall be not less than 95 % of the theoretical speed.